1. Field of the Invention
The invention herein relates to electrical cable, such as television transmission cable, and connectors therefor. More particularly, it pertains to cover devices to protect such connectors from the ambient environment.
2. Description of the Prior Art
Many cable connections are positioned where they are subject to adverse ambient environments, particularly where the connection will be subject to moisture contact from rain, snow or humidity. A typical example is a connection for a television signal transmission cable, where the cable is attached to a transmission facility outlet, a retransmission station or a subscriber's connection, such as a residence. Some protection may be afforded by enclosing the connection in a housing, such as the small junction boxes for subscriber hookups commonly seen in residential neighborhoods. However, such housings are not completely weather-tight, and in any event many connections remain in the open, or are located in positions where housings are not practical.
Further, in many cases connections must be made during adverse weather. If, for instance, a cable television circuit or an electric power circuit goes out because of a heavy rainstorm, the immediate demands for restored service by the subscribers require the transmission company to send repair people to make the necessary repairs to the cable as quickly as possible, notwithstanding that the storm may be continuing. Such repairs to a large extent require the installation of new connectors, either for cable splices or for re-connection to transmission or receiving facilities. However, to minimize potential damage to the connectors, their exposure to the elements should be as brief as possible. This requirement for brief exposure (i.e., quick repair) is of course reinforced by the fact that commonly during such a storm there are many service disruptions and the repair people need to spend as little time as possible repairing each individual connection so that they will be able to move quickly to restore service systemwide.
It has been known for some time that it is advantageous to cover such cable connections (whether television transmission cable or other types of electrical cable) to minimize the exposure of the connections to the elements, particularly to moisture. Since the cable segments themselves have moisture impervious coverings throughout their length, the particularly vulnerable portions of a cable system are the individual connectors, which are usually screw-type or soldered metal fittings. Wrapping such connectors with moisture-resistant tape has not proved satisfactory, since the adhesive holding the tape does not adhere well to wet surfaces to start with, and even if initially well-adhered, tends to deteriorate with age and the tape becomes loosened. In addition, tape wrapping is a time consuming procedure and often difficult to do properly in cramped or enclosed locations.
Heat shrinkable tubing has also been used to cover connections. Heat shrinkable tubing is tubing made of thermoplastic polymeric materials which, when subjected to elevated temperatures, shrink and contract around the connection. While such heat shrink tubing has proved more effective than tape wrapping, it still has a number of serious deficiencies. For instance, heat shrinking takes a considerable amount of time for the large diameter, relatively thick wall tubing necessary to use with large diameter cable connectors. Thus, cable installers or repair crews find that while the cable connections themselves may be made quickly, an inordinate amount of time must subsequently be spent slowly shrinking the heat shrink tubing to fit. The shrinking cannot be expedited by applying additional heat. The additional heat will simply char and damage the plastic tubing, rather than appreciably speeding the shrinking process. Further, excessive heat applied to the cable protector will also damage the foam dielectric component of the cable itself. Of course, in many instances, particularly at remote locations, a suitable source of heat is not available to the installation or repair crew. Similarly, in many installations the positioning of the connection is such that even where a heating source is available, the heat cannot be applied evenly to the tubing because the access by the heat source is restricted. Thus, the use of heat shrinkable tubing has had only limited applicability and has been essentially unsuitable where rapid installation or repair is needed to limit the exposure of the connections to the elements.
Protectors using chemical dilation and shrinking have been considered in the past, but until recently were not practical. Those materials preferentially used in the industry had a limited degree of diameter change, and the variations in diameters of cables and cable connection hardware were greater than the structure of such prior art cable protectors utilizing chemical dilation could accommodate. Recently, however, new protector products which are chemically dilatable over an appropriate range of cable and cable connector sizes have been formulated and developed by one of the applicants herein. The new protector products have met with substantial success in the field, since they are easy to install and use and provide for superior protection as compared to the competitive materials. The new products are the subject of pending U.S. patent application Ser. No. 08/541,135, filed Oct. 11, 1995, by co-inventor Michael G. Jones.
Those new products, while quite successful, have (like the prior art products before them) been recognized as having a pervasive and disagreeable odor, due to the nature of the dilation solvents which have been necessary for their manufacture and operation. While odor does not affect their superior installation and performance, it is annoying and unpleasant to the installation workers who must handle the products and can affect the ambient environment for a time, especially when the protectors are installed in a confined space. Until now, however, no formulations of solvents were known which did not have a harsh odor of some kind and yet were effective for dilation of the new products. Different solvents were known to have different odors, but all were pervasive, disagreeable and much disliked by the installation workers.